The IUPAC name of the complex `K_(2)[Ni (CN)_(4)]` is

Options

A. Tetrapotassiumtetracyanonickelate (0)
B. Potassiumtetracyanonickel (0)
C. Potassium tetracyanonickelate (II)
D. Tetrapotassiumtetracyanonickel (0)

Answer

To determine the IUPAC name of the complex \( K_2[Ni(CN)_4] \), we can follow these steps:

### Step 1: Identify the components of the complex
The complex \( K_2[Ni(CN)_4] \) consists of a cationic part (potassium ions) and an anionic complex (the nickel cyanide complex).

### Step 2: Dissociate the complex
When dissociated, the complex can be represented as:
\[ 2K^+ + [Ni(CN)_4]^{2-} \]
Here, \( 2K^+ \) is the cation and \( [Ni(CN)_4]^{2-} \) is the anionic complex.

### Step 3: Determine the oxidation state of nickel
Let the oxidation state of nickel be \( x \). The cyanide ion \( CN^- \) has a charge of -1. Since there are 4 cyanide ions, their total contribution to the charge is -4. The overall charge of the complex is -2. Therefore, we can set up the equation:
\[ x + (-4) = -2 \]
Solving for \( x \):
\[ x - 4 = -2 \\ x = +2 \]
Thus, the oxidation state of nickel in this complex is +2.

### Step 4: Name the cation
The cation in this complex is potassium. Since there are 2 potassium ions, we simply write "potassium" without indicating the number in the name.

### Step 5: Name the anionic complex
The anionic part consists of the ligand cyanide. Since there are 4 cyanide ligands, we use the prefix "tetra" to indicate this. The name of the ligand is "cyano".

### Step 6: Name the metal in the anionic complex
Since the metal (nickel) is part of an anionic complex, we change its name to "nickelate" and indicate its oxidation state in Roman numerals. Therefore, we write "nickelate(II)" to indicate that nickel is in the +2 oxidation state.

### Step 7: Combine the names
Now, we combine the names of the cation and anionic complex:
\[ \text{Potassium tetra cyano nickelate(II)} \]

### Final Answer
The IUPAC name of the complex \( K_2[Ni(CN)_4] \) is:
\[ \text{Potassium tetra cyano nickelate(II)} \]

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